Proteomics Peptides & KitsPeptide sets and pools, as well as assay standardization kits are available with stable isotope labeled or unlabeled proteotypic peptides for mass-spectrometry based proteomics such as MRM assays.

Chelate Peptides (DOTA)DOTA is linked to molecules that have affinity for various structures (e.g. somatostatin receptors in neuroendocrine tumors). The resulting compounds can be bound to radionuclided and are used with a number of radioisotopes in cancer therapy and diagnosis

Immunology Standards & ControlsStandards and controls for reproducible T-cell assays such as ELISPOT and multimer assays. We offer a large variety of positive and negative control peptide pools for antigen specific T cell stimulation as well as kit to produce TCR-engineered reference samples for performance control.

Antigen PeptidesAntigen peptides represent specific epitopes for stimulation of T cells in T cell assays such as ELISPOT. We offer the corresponding MHC multimer for each antigen peptide. Antigens from different pathogens are available as well as tumor associated antigens.

Cosmetic PeptidesCosmetic Peptides such as Lysine and Cysteine Peptide are used for DPRA (Direct Peptide Reactivity Assay) for Skin Sensitization Testing. The DPRA measures the reaction of a chemical with synthetic peptides containing Cysteine (Ac‑RFAACAA‑COOH) or Lysine (Ac‑RFAAKAA‑COOH) to assess its sensitization potency. For research use only!

A Novel Strategy for the Rapid Preparation and Isolation of Intact Immune Complexes from Peptide Mixtures

Al-Majdoub et al., J Mol Recognit. (2014) - PMID: 25042711

The development and application of a miniaturized affinity system for the preparation and release of intact immune complexes are demonstrated. Antibodies were reversibly affinity-adsorbed on pipette tips containing protein G´ and protein A, respectively. Antigen proteins were digested with proteases and peptide mixtures were exposed to attached antibodies; forming antibody-epitope complexes, that is, immune complexes. Elution with millimolar indole propionic acid (IPA)-containing buffers under neutral pH conditions allowed to effectively isolate the intact immune complexes in purified form. Size exclusion chromatography was performed to determine the integrity of the antibody-epitope complexes. Mass spectrometric analysis identified the epitope peptides in the respective SEC fractions. His-tag-containing recombinant human glucose-6-phosphate isomerase in combination with an anti-His-tag monoclonal antibody was instrumental to develop the method. Application was extended to the isolation of the intact antibody-epitope complex of a recombinant human tripartite motif 21 (rhTRIM21) auto-antigen in combination with a rabbit polyclonal anti-TRIM21 antibody. Peptide chip analysis showed that antibody-epitope binding of rhTRIM21 peptide antibody complexes was not affected by the presence of IPA in the elution buffer. By contrast, protein G´ showed an ion charge structure by electrospray mass spectrometry that resembled a denatured conformation when exposed to IPA-containing buffers. The advantages of this novel isolation strategy are low sample consumption and short experimental duration in addition to the direct and robust methodology that provides easy access to intact antibody-antigen complexes under neutral pH and low salt conditions for subsequent investigations.